1. Field of the Invention
The present invention relates to a method and apparatus for encoding and decoding multi-view video, and more particularly, to a method and apparatus for encoding and decoding multi-view video to provide uniform picture quality with respect to different viewpoints.
2. Description of the Related Art
FIG. 1 illustrates an example of a multi-view video input system.
As illustrated in FIG. 1, multi-view video is a plurality of video frames taken by and received from a plurality of cameras, each of which is at a different viewpoint. Accordingly, an apparatus for encoding multi-view video receives a plurality of video frames taken at different viewpoints from a plurality of cameras. Accordingly, multi-view video generally requires a large amount of data storage space, and compression-encoding is essential in order to effectively provide three-dimensional (3D) services using multi-view video.
Recently, as a standard for multi-view encoding, a motion video experts group 2 multi-view profile (MPEG-2 MVP) was proposed. Also, the MPEG is a work group that prepares the 3D-AV standards. The MPEG-2 MVP standard is limited in use to stereo video, while the MPEG 3D-AV standard has been prepared to standardize encoding multi-view video corresponding to camera arrays, such as 1-D parallel, 2-D parallel, 1-D arc, etc.
FIG. 2 is a view for explaining an example to which the MPEG-2 MVP is applied.
According to the MPEG-2 MVP standard, when 3D video is encoded using a left view video frame and a right view video frame, the 3D video is encoded and reproduced using a scalable codec for detecting correlation between the two video frames and variably encoding a difference between the two video frames according to a network status. Here, the encoding is performed under an assumption that the left view video frame is a base layer video frame and the right view video frame is an enhancement layer video frame. The base layer video frame is a video frame which can be encoded using only its own information, and the enhancement layer video frame is a video frame which is additionally encoded and transmitted in order to enhance the picture quality of the base layer video frame when the network is stable. As such, encoding using base layer video frames and enhancement layer video frames is called “scalable coding”.
In FIG. 2, the left view video frame, which is a base layer video frame, is encoded by a method such as the existing main profile, without using disparity information of video frames taken at different viewpoints. That is, the left view video frame is encoded using intra coding and motion compensation coding in order to reduce spatial and temporal redundancy. Meanwhile, the right view video frame is encoded by performing disparity estimation on the left view video frame and performing motion estimation on a right view video frame. However, since the MPEG-2 MVP specification does not consider an encoder for encoding multi-view video, the MPEG-2 MVP specification is not actually suitable for multi-view video. Therefore, an encoder for efficiently providing multi-view video in order to simultaneously provide a stereoscopic effect and realism to a plurality of people is necessary.